Greetings all. I am new to the site and the medium. I have come seeking help with a project.

I have a pair of fountain pens with ABS plastic barrels that I love dearly, but I would like to modify them to accept rollerball refills. As the pens are plastic, I had the idea to scan the front section of the pen where the nib is and modify the shape into what I want, 3D-print the modified section, and I have a new pen! The original product has been defunct for about ten years, thus precluding me from simply acquiring another. Help is appreciated; thank you kindly.